Perovskite solar cell, preparation method thereof, cell module and laminated cell

Abstract

The invention discloses a perovskite solar cell, a preparation method thereof, a cell module and a laminated cell. The perovskite solar cell comprises a composite hole transport layer and a perovskite light absorption layer, the perovskite light absorption layer is located on one side of the composite hole transport layer, and the composite hole transport layer comprises polyvinyl acetate and an SAM material. Therefore, the polyvinyl acetate is of a cross-linked network structure and can play a role in stabilizing the SAM material and inhibiting the SAM material from diffusing to the perovskite light absorption layer, so that the stability of the self-assembled monomolecular layer is improved, and the stability of the perovskite solar cell is improved; in the perovskite solar cell, carbonyl oxygen in polyvinyl acetate can be coordinated with uncoordinated metal ions in the perovskite light absorption layer to realize passivation of a bottom interface of the perovskite light absorption layer, so that interface recombination is reduced, and the performance of the perovskite solar cell is improved.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular, to perovskite solar cells, their preparation methods, battery modules, and tandem cells. Background Art

[0002] Thanks to the development of perovskite film-forming technology and its own material technology, the photoelectric conversion efficiency of perovskite solar cell technology has been significantly improved in the past decade. Currently, developing efficient, stable, and low-cost charge transport materials, especially hole transport materials (HTM), is crucial for promoting the commercialization of perovskite solar cells (PSC).

[0003] The self-assembly strategy based on anchoring has been proven to be able to construct an efficient hole transport layer for high-performance p-i-n structured PSC. This process uses self-assembled molecular HTM, which includes anchoring groups (such as carboxyl groups), and these groups can spontaneously adsorb onto the surface of the oxide substrate to form a monolayer coverage. Compared with the traditional thick hole transport layer (HTL) based on spin coating or spray pyrolysis, the self-assembled monolayer has the advantages of less material consumption and low parasitic absorption.

[0004] However, the currently reported self-assembled monolayers still have problems of insufficient stability and poor wettability. In large-area preparation, there are also problems of poor uniformity, which easily leads to leakage current; in addition, the performance of perovskite solar cells also needs to be improved. Summary of the Invention

[0005] The present application aims to at least partially alleviate or solve at least one of the above-mentioned problems.

[0006] In one aspect of the present application, the present application provides a perovskite solar cell. In some embodiments of the present application, the perovskite solar cell includes a composite hole transport layer and a perovskite light-absorbing layer. The perovskite light-absorbing layer is located on one side of the composite hole transport layer, and the composite hole transport layer includes polyvinyl acetate and SAM material. Thus, polyvinyl acetate has a cross-linked network structure, which can play a role in stabilizing the SAM material, inhibiting the diffusion of the SAM material into the perovskite light-absorbing layer, thereby improving the stability of the self-assembled monolayer and being beneficial to improving the stability of the perovskite solar cell; the carbonyl oxygen in polyvinyl acetate can coordinate with the uncoordinated metal ions in the perovskite light-absorbing layer to achieve passivation of the bottom interface of the perovskite light-absorbing layer, thereby reducing interface recombination and improving the performance of the perovskite solar cell.

[0007] In some embodiments of the present application, the mass ratio of the SAM material to the polyvinyl acetate is 5:1 to 30:1. Thus, it is beneficial to further improve the stability of the self-assembled monolayer.

[0008] In some embodiments of the present application, the SAM material includes one or more of a phosphoric acid anchored material with carbazole as the core and a phosphoric acid anchored material with acridine as the core. The above materials can all form self-assembled monolayers and play a role in hole transport.

[0009] In some embodiments of the present application, the SAM material includes one or more of (2-(9H-carbazol-9-yl)ethyl)phosphonic acid, [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid, (4-(3,6-dimethyl-9H-carbazol-9-yl)butyl)phosphonic acid, [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid, [4-(9H-carbazol-9-yl)butyl]phosphonic acid, (4-(3,6-dibromo-9H-carbazol-9-yl)butyl)phosphonic acid, (2-(3,6-dimethyl-9H-carbazol-9-yl)ethyl)phosphonic acid, (2-(3,6-dibromo-9H-carbazol-9-yl)ethyl)phosphonic acid, [4-(2,7-dibromo-9,9-dimethylacridin-10-yl)butyl]phosphate, [4-(2,7-dimethyl-9,9-dimethylacridin-10-yl)butyl]phosphate, [4-(2,7-diphenyl-9,9-dimethylacridin-10-yl)butyl]phosphate. The above materials have good hole transport performance, which is beneficial to improving the overall performance of perovskite solar cells.

[0010] In some embodiments of the present application, the perovskite light-absorbing layer includes a perovskite material, and the general formula of the perovskite material is ABX 3 , where A includes MA + , FA + , Cs + one or more of them, B includes Pb 2+ , Sn 2+ one or more of them, and X includes I - , Br - , Cl - one or more of them. The above perovskite materials can absorb sunlight and provide a basis for achieving high-efficiency photoelectric conversion.

[0011] In some embodiments of the present application, the perovskite solar cell further includes: a conductive glass, which includes a glass substrate and a first electrode layer, and the first electrode layer is disposed close to the composite hole transport layer; an electron transport layer, which is located on the side of the perovskite light-absorbing layer away from the composite hole transport layer; a second electrode layer, which is located on the side of the electron transport layer away from the perovskite light-absorbing layer. Thus, it is beneficial to further improve the overall performance of the perovskite solar cell.

[0012] In some embodiments of the present application, the perovskite solar cell satisfies at least one of the following conditions: the first electrode layer includes one or more of ITO, FTO, AZO, and GZO; the electron transport layer includes one or more of [6,6]-phenyl-C61-butyric acid methyl ester, C60, and tin oxide; the second electrode layer includes one or more of silver, copper, carbon, and conductive oxides; the perovskite solar cell further includes an inorganic hole transport layer, and the inorganic hole transport layer is located between the conductive glass and the composite hole transport layer; the perovskite solar cell further includes a hole blocking layer, the hole blocking layer is located between the electron transport layer and the second electrode layer, and the hole blocking layer includes one or more of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline and zirconium acetylacetonate.

[0013] In another aspect of the present application, the present application provides a method for preparing a perovskite solar cell. In some embodiments of the present application, the method for preparing a perovskite solar cell includes: forming a composite hole transport layer, the composite hole transport layer including polyvinyl acetate and SAM material; forming a perovskite light-absorbing layer on one side of the composite hole transport layer. Thus, polyvinyl acetate has a cross-linked network structure, which can play a role in stabilizing the SAM material, inhibiting the diffusion of the SAM material into the perovskite light-absorbing layer, thereby improving the stability of the self-assembled monolayer and being beneficial to improving the stability of the perovskite solar cell; the carbonyl oxygen in polyvinyl acetate can coordinate with the uncoordinated metal ions in the perovskite light-absorbing layer to achieve passivation of the bottom interface of the perovskite light-absorbing layer, thereby reducing interface recombination and enhancing the performance of the perovskite solar cell; the ester group can improve the wettability of the composite hole transport layer, contribute to the large-area uniform film formation of the perovskite, and is beneficial to the preparation of large-area cells.

[0014] In some embodiments of the present application, forming the composite hole transport layer includes: providing a dispersion liquid, the dispersion liquid including SAM material, vinyl acetate, and a dispersant; forming the composite hole transport layer by coating the dispersion liquid and performing an annealing treatment. Small molecule vinyl acetate can achieve thermal cross-linking during the annealing treatment to form polyvinyl acetate with a cross-linked network structure, curing and stabilizing the self-assembled monolayer, enhancing the stability of the self-assembled monolayer, and avoiding its diffusion into the perovskite light-absorbing layer, thereby being beneficial to enhancing the performance of the perovskite solar cell.

[0015] In some embodiments of the present application, the method for preparing a perovskite solar cell satisfies at least one of the following conditions: in the dispersion liquid, the mass ratio of the SAM material to vinyl acetate is 5:1 to 30:1; the total concentration of the SAM material and vinyl acetate is 0.1 mg / mL to 2 mg / mL; the dispersant includes one or more of ethanol and isopropanol; the method for coating the dispersion liquid includes one or more of spin coating, blade coating, and slot coating; the temperature of the annealing treatment is 60°C to 150°C; the time of the annealing treatment is 1 minute to 120 minutes. Thus, it is beneficial to form a composite hole transport layer with excellent performance.

[0016] In some embodiments of the present application, the material for forming the perovskite light-absorbing layer includes a first perovskite precursor and a second perovskite precursor. The first perovskite precursor includes one or more of lead halide salts and tin halide salts, and the second perovskite precursor includes one or more of formamidinium halide salts, methylammonium halide salts, and cesium halide salts. The perovskite light-absorbing layer formed by using the above precursors can absorb sunlight and provide a basis for realizing photoelectric conversion.

[0017] In another aspect of the present application, the present application proposes a battery module. In some embodiments of the present application, it includes a plurality of the above-mentioned perovskite solar cells or perovskite solar cells prepared by using the above-mentioned method. Thus, the battery module has all the characteristics and advantages of the above-mentioned perovskite solar cells, which will not be elaborated here.

[0018] In another aspect of the present application, the present application proposes a tandem cell. In some embodiments of the present application, the tandem cell includes a first cell and a second cell arranged in a stacked manner, and at least one of the first cell and the second cell includes the above-mentioned perovskite solar cell or a perovskite solar cell prepared by using the above-mentioned method. Thus, the tandem cell has all the characteristics and advantages of the above-mentioned perovskite solar cells, which will not be elaborated here. Description of the Drawings

[0019] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description of the embodiments in conjunction with the accompanying drawings, where:

[0020] Figure 1 Shows a schematic structural diagram of a perovskite solar cell according to an embodiment of the present application;

[0021] Figure 2 Shows a schematic structural diagram of a perovskite solar cell according to another embodiment of the present application;

[0022] Figure 3Shows a schematic structural diagram of a perovskite solar cell according to another embodiment of the present application;

[0023] Figure 4 Shows a schematic structural diagram of a perovskite solar cell according to another embodiment of the present application;

[0024] Figure 5 Shows a schematic structural diagram of a tandem cell according to an embodiment of the present application.

[0025] Explanation of reference numerals:

[0026] 10: Composite hole transport layer; 20: Perovskite light-absorbing layer; 30: Conductive glass; 31: Glass substrate; 32: First electrode layer; 40: Electron transport layer; 50: Second electrode layer; 60: Hole blocking layer; 70: Inorganic hole transport layer; 1: First cell; 2: Second cell. Detailed description of the specific implementation

[0027] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application and should not be construed as a limitation of the present application.

[0028] In one aspect of the present application, the present application proposes a perovskite solar cell. In some embodiments of the present application, referring to Figures 1 to 4 , the perovskite solar cell may include a composite hole transport layer 10 and a perovskite light-absorbing layer 20. The perovskite light-absorbing layer 20 is located on one side of the composite hole transport layer 10. The composite hole transport layer 10 includes polyvinyl acetate and SAM (Self-Assembled Monolayers) material. Thus, the polyvinyl acetate has a cross-linked network structure, which can play a role in stabilizing the SAM material, inhibiting the diffusion of the SAM material to the perovskite light-absorbing layer, thereby improving the stability of the self-assembled monolayer, and further being beneficial to improving the stability of the perovskite solar cell; in addition, the carbonyl group in the polyvinyl acetate can effectively enhance the defect passivation function of the composite hole transport layer. Specifically, the carbonyl oxygen in the polyvinyl acetate can coordinate with the uncoordinated metal ions in the perovskite light-absorbing layer to achieve the passivation of the bottom interface of the perovskite light-absorbing layer, thereby reducing the recombination of holes and electrons at this interface and being beneficial to improving the performance of the perovskite solar cell.

[0029] In some embodiments of the present application, the SAM material may include, but is not limited to, one or more of a phosphoric acid-anchored material with carbazole as the core and a phosphoric acid-anchored material with acridine as the core. The above materials can all form self-assembled monolayers and play a role in hole transport. Among them, the carbazole and acridine groups have good optoelectronic properties (such as hole transport properties), and the phosphoric acid group can form a strong binding force with the underlying film layer or structure.

[0030] In some embodiments of the present application, the SAM material may include one or more of (2-(9H-carbazol-9-yl)ethyl)phosphonic acid (2PACz), [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz), (4-(3,6-dimethyl-9H-carbazol-9-yl)butyl)phosphonic acid (Me-4PACz), [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid (MeO-4PACz), [4-(9H-carbazol-9-yl)butyl]phosphonic acid (4PACz), (4-(3,6-dibromo-9H-carbazol-9-yl)butyl)phosphonic acid (Br-4PACz), (2-(3,6-dimethyl-9H-carbazol-9-yl)ethyl)phosphonic acid (Me-2PACz), (2-(3,6-dibromo-9H-carbazol-9-yl)ethyl)phosphonic acid (Br-2PACz), [4-(2,7-dibromo-9,9-dimethylacridin-10-yl)butyl]phosphoric acid (DMACPA), [4-(2,7-dimethyl-9,9-dimethylacridin-10-yl)butyl]phosphoric acid, [4-(2,7-diphenyl-9,9-dimethylacridin-10-yl)butyl]phosphoric acid. The above materials have excellent hole transport properties, which is beneficial to improving the overall performance of perovskite solar cells.

[0031] In some specific embodiments, the SAM material in the composite hole transport layer 10 may include 2PACz, MeO-2PACz, Me-4PACz, MeO-4PACz, 4PACz, Br-4PACz, Me-2PACz, Br-2PACz, [4-(2,7-dibromo-9,9-dimethylacridin-10-yl)butyl]phosphonic acid (DMACPA), [4-(2,7-dimethyl-9,9-dimethylacridin-10-yl)butyl]phosphonic acid, or [4-(2,7-diphenyl-9,9-dimethylacridin-10-yl)butyl]phosphonic acid. In some other specific embodiments, the SAM material in the composite hole transport layer 10 may include two or more of 2PACz, MeO-2PACz, Me-4PACz, MeO-4PACz, 4PACz, Br-4PACz, Me-2PACz, Br-2PACz, [4-(2,7-dibromo-9,9-dimethylacridin-10-yl)butyl]phosphonic acid (DMACPA), [4-(2,7-dimethyl-9,9-dimethylacridin-10-yl)butyl]phosphonic acid, [4-(2,7-diphenyl-9,9-dimethylacridin-10-yl)butyl]phosphonic acid.

[0032] In some embodiments of the present application, in the composite hole transport layer 10, the mass ratio of the SAM material to polyvinyl acetate may be 5:1 to 30:1. For example, the mass ratio of the SAM material to polyvinyl acetate may be 5:1, 10:1, 15:1, 20:1, 25:1, or 30:1. Thus, the polyvinyl acetate crosslinked network structure can more effectively inhibit the diffusion of SAM to the perovskite light-absorbing layer, which is beneficial to further improving the stability of the self-assembled monolayer; the higher content of the SAM material in the composite hole transport layer is beneficial to improving the hole transport ability of the composite hole transport layer, which is beneficial to improving the photoelectric conversion efficiency of the perovskite solar cell.

[0033] In some embodiments of the present application, the perovskite light-absorbing layer 20 includes a perovskite material, and the general formula of the perovskite material may be ABX 3 , where A is a monovalent cation, and A may include MA + (methylammonium ion), FA + (formamidinium ion), Cs + or one or more of them, B is a divalent cation, and B may include Pb 2+ , Sn 2+ or one or more of them, and X is a monovalent anion, and X may include I - , Br - , Cl - or one or more of them. The above perovskite material can absorb sunlight, providing a basis for achieving high-efficiency photoelectric conversion.

[0034] In some embodiments of the present application, the perovskite material may include MAPbI 3 , FAPbI 3 , CsPbI 3 , MA a FA 1- a PbI 3 (0 < a < 1), Cs b FA 1-b PbI 3 (0 < b < 1), Cs c MA 1-c PbI 3 (0 < c < 1), MAPbI 3-d Br d (0 < d < 3) or MAPbI 3-e Cl e (0 < e < 3).

[0035] In some embodiments of the present application, the perovskite solar cell may be a p-i-n type inverted perovskite solar cell.

[0036] In some embodiments of the present application, referring to Figures 2 to 4 , the perovskite solar cell may further include a conductive glass 30, an electron transport layer 40, and a second electrode layer 50.

[0037] In some embodiments of the present application, referring to Figures 2 to 4 , the conductive glass 30 may include a glass substrate 31 and a first electrode layer 32, and the first electrode layer 32 is disposed close to the composite hole transport layer 10; the electron transport layer 40 is located on the side of the perovskite light absorption layer 20 away from the composite hole transport layer 10; the second electrode layer 50 is located on the side of the electron transport layer 40 away from the perovskite light absorption layer 20. Thus, it is beneficial to further improve the overall performance of the perovskite solar cell.

[0038] In some embodiments of the present application, the first electrode layer 32 includes one or more of ITO (indium tin oxide), FTO (fluorine-doped tin oxide), AZO (aluminum-doped zinc oxide), and GZO (gallium-doped zinc oxide). The above materials have good electrical conductivity and light transmittance, which is beneficial to further improve the performance of the perovskite solar cell. In some specific embodiments, the first electrode layer is an indium tin oxide layer.

[0039] In some embodiments of the present application, referring to Figure 2 and Figure 3 , the composite hole transport layer 10 may be located on the surface of the conductive glass 30 provided with the first electrode layer 32.

[0040] In some other embodiments of the present application, referring to Figure 4, the perovskite solar cell may further include an inorganic hole transport layer 70, and the inorganic hole transport layer 70 is located between the conductive glass 30 and the composite hole transport layer 10. In some embodiments of the present application, the inorganic hole transport layer 70 may include one or more of nickel oxide and copper oxide. The above materials have high hole transport ability, which is beneficial to further improving the performance of the perovskite solar cell.

[0041] In some embodiments of the present application, the electron transport layer 40 may include one or more of [6,6]-phenyl-C61-butyric acid methyl ester, C60, and tin oxide. In some embodiments, the electron transport layer 40 may include [6,6]-phenyl-C61-butyric acid methyl ester, C60, or tin oxide. In other embodiments, the electron transport layer 40 may include two or three of [6,6]-phenyl-C61-butyric acid methyl ester, C60, and tin oxide. The above materials all have good electron transport ability, which is beneficial to further improving the performance of the solar cell.

[0042] In some embodiments of the present application, the second electrode layer 50 may include one or more of silver, copper, carbon, and conductive oxides (such as ITO, IZO (indium zinc oxide), etc.).

[0043] In some embodiments of the present application, refer to Figure 2 , the second electrode layer 50 may be disposed on the surface of the electron transport layer 40 away from the perovskite light-absorbing layer 20.

[0044] In other embodiments of the present application, refer to Figure 3 , the perovskite solar cell may further include a hole blocking layer 60, and the hole blocking layer 60 is located between the electron transport layer 40 and the second electrode layer 50. In some embodiments, the hole blocking layer 60 may include one or more of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline and zirconium acetylacetonate. The above materials can prevent holes from passing through and reduce recombination loss, thereby being beneficial to improving the photoelectric conversion efficiency of the perovskite solar cell.

[0045] In some embodiments of the present application, the perovskite solar cell may be a small cell (with a small size).

[0046] In other embodiments of the present application, the perovskite solar cell may also be a solar cell module with a larger size.

[0047] On the other hand of the present application, the present application proposes a method for preparing a perovskite solar cell. In some embodiments of the present application, the method for preparing a perovskite solar cell may include the following steps:

[0048] S10: Form a composite hole transport layer.

[0049] In some embodiments of the present application, the composite hole transport layer includes polyvinyl acetate and SAM material. The SAM material has been described in detail above and will not be elaborated here.

[0050] In some embodiments of the present application, forming the composite hole transport layer includes the following steps:

[0051] S11: Provide a dispersion.

[0052] In some embodiments of the present application, the dispersion may include SAM material, vinyl acetate, and a dispersant.

[0053] In some embodiments of the present application, the dispersant may include one or more of ethanol and isopropanol. The SAM material and vinyl acetate can be uniformly dispersed in ethanol or isopropanol to form a uniform dispersion, which is convenient for subsequent coating to form a film layer with better consistency.

[0054] In some embodiments of the present application, in the dispersion, the mass ratio of the SAM material to vinyl acetate may be from 5:1 to 30:1. For example, the mass ratio of the SAM material to vinyl acetate may be 5:1, 10:1, 15:1, 20:1, 25:1, or 30:1. The SAM material has excellent hole transport ability, and a higher content of the SAM material is beneficial to improving the hole transport ability of the composite hole transport layer; vinyl acetate can in-situ thermally crosslink to form a crosslinked network structure during subsequent processing, curing and stabilizing the SAM, which is thus beneficial to improving the stability of the composite hole transport layer.

[0055] In some embodiments of the present application, in the dispersion, the total concentration of the SAM material and vinyl acetate may be from 0.1 mg / mL to 2 mg / mL. For example, the total concentration of the SAM material and vinyl acetate may be 0.1 mg / mL, 0.3 mg / mL, 0.5 mg / mL, 0.7 mg / mL, 1 mg / mL, 1.2 mg / mL, 1.5 mg / mL, 1.8 mg / mL, or 2 mg / mL. Thereby, it is beneficial to the full dissolution of the SAM material and vinyl acetate, and it is also beneficial to fully cover the underlying structure (such as conductive glass) to form a film layer with better consistency.

[0056] S12: Form a composite hole transport layer by coating the dispersion and performing annealing treatment.

[0057] In some embodiments of the present application, the method of coating the dispersion may include one or more of spin coating, blade coating, and slot die coating. Thereby, it is beneficial to form a uniform coating. In some embodiments, the dispersion may be coated by spin coating, blade coating, or slot die coating. In other embodiments, the dispersion may be coated by two or more of spin coating, blade coating, and slot die coating.

[0058] In some embodiments of the present application, the temperature of the annealing treatment can be from 60°C to 150°C. For example, the temperature of the annealing treatment can be 60°C, 80°C, 100°C, 120°C, or 150°C. When the annealing temperature is within the above range, it is beneficial to the in-situ thermal cross-linking polymerization of vinyl acetate to form a cross-linked network structure.

[0059] In some embodiments of the present application, the time of the annealing treatment can be from 1 minute to 120 minutes. Thereby, it is beneficial to the sufficient reaction of vinyl acetate to form a composite hole transport layer with excellent performance.

[0060] In some embodiments of the present application, the time of the annealing treatment can be from 20 minutes to 120 minutes. For example, the time of the annealing treatment can be 20 minutes, 30 minutes, 50 minutes, 80 minutes, 100 minutes, or 120 minutes. Thereby, the dispersant can be sufficiently removed, and vinyl acetate can be sufficiently cross-linked and polymerized to form a cross-linked network structure.

[0061] Small molecule vinyl acetate can achieve thermal cross-linking during the annealing treatment to form polyvinyl acetate with a cross-linked network structure, solidify and stabilize the self-assembled monolayer, improve the stability of the self-assembled monolayer, and prevent the self-assembled monolayer from diffusing into the perovskite light-absorbing layer during the preparation of the perovskite light-absorbing layer or after the formation of the perovskite light-absorbing layer. Thus, it is beneficial to improve the performance of the perovskite solar cell; the ester group can improve the wettability of the composite hole transport layer, and the ester group in polyvinyl acetate helps the subsequent perovskite light-absorbing layer to form a large-area uniform film, which is beneficial to the preparation of large-area cells.

[0062] S20: Form a perovskite light-absorbing layer on one side of the composite hole transport layer.

[0063] In some embodiments of the present application, the materials for forming the perovskite light-absorbing layer can include a first perovskite precursor and a second perovskite precursor. Among them, the first perovskite precursor can include one or more of lead halide salts (such as lead iodide, lead bromide, lead chloride, etc.) and tin halide salts (such as tin iodide, selenium bromide, tin chloride, etc.), and the second perovskite precursor can include one or more of formamidinium halide salts (such as FAI, FABr, FACl, etc.), methylammonium halide salts (such as MAI, MABr, MACl, etc.), and cesium halide salts (such as CsI, CsBr, CsCl, etc.). The perovskite light-absorbing layer formed by using the above precursors can absorb sunlight and provide a basis for realizing photoelectric conversion.

[0064] In some embodiments, the first perovskite precursor and the second perovskite precursor can be dissolved in N,N-dimethylformamide (DMF) to form a perovskite precursor solution. The perovskite precursor solution is coated on one side of the composite hole transport layer, and then heated and annealed to form a perovskite light-absorbing layer. The concentration of the perovskite precursor solution, the ratio of the first precursor to the second precursor, the coating method of the perovskite precursor solution, the annealing temperature and time, etc. are not particularly limited in this application, and those skilled in the art can set them according to actual needs.

[0065] By using the above method, a composite hole transport layer with stable performance can be formed. Specifically, polyvinyl acetate has a cross-linked network structure, which can play a role in stabilizing the SAM material, inhibiting the diffusion of the SAM material into the perovskite light-absorbing layer, thereby improving the stability of the self-assembled monolayer and being beneficial to improving the stability of the perovskite solar cell; the carbonyl oxygen in polyvinyl acetate can coordinate with the uncoordinated metal ions in the perovskite light-absorbing layer to achieve passivation of the bottom interface of the perovskite light-absorbing layer, thereby reducing interface recombination and enhancing the performance of the perovskite solar cell; the ester group can improve the wettability of the composite hole transport layer, contribute to the large-area uniform film formation of perovskite, and is beneficial to the preparation of large-area batteries.

[0066] In some embodiments of the present application, the method for preparing a perovskite solar cell may further include steps such as forming an electron transport layer and forming a second electrode layer.

[0067] In some embodiments, the method for preparing a perovskite solar cell further includes a step of forming a hole blocking layer on the side of the electron transport layer away from the perovskite light-absorbing layer. After forming the hole blocking layer, a second electrode layer is formed on the side of the hole blocking layer away from the perovskite light-absorbing layer.

[0068] In another aspect of the present application, the present application proposes a battery module. In some embodiments of the present application, it includes a plurality of the aforementioned perovskite solar cells or perovskite solar cells prepared by using the aforementioned method. Thus, the battery module has all the characteristics and advantages of the aforementioned perovskite solar cell, which will not be elaborated herein.

[0069] In some embodiments of the present application, the plurality of perovskite solar cells in the battery module are connected together in series or in parallel to form a larger-area power generation unit.

[0070] In another aspect of the present application, the present application proposes a tandem cell. In some embodiments of the present application, refer to Figure 5, the tandem cell includes a first cell 1 and a second cell 2 which are stacked. At least one of the first cell 1 and the second cell 2 includes the perovskite solar cell described above or the perovskite solar cell prepared by the method described above. Thus, the tandem cell has all the characteristics and advantages of the perovskite solar cell described above, which will not be elaborated here.

[0071] In some embodiments of the present application, the tandem cell can be a crystalline silicon-perovskite tandem cell, a perovskite-perovskite tandem cell, a perovskite-copper indium gallium selenide tandem cell, a perovskite-gallium arsenide tandem cell, etc.

[0072] In some embodiments of the present application, the tandem cell can be based on a battery module.

[0073] The present application will be described below through specific embodiments. Those skilled in the art can understand that the following specific embodiments are only for the purpose of illustration and do not limit the scope of the present application in any way. Additionally, in the following embodiments, unless otherwise specified, the materials and equipment used are commercially available. If the specific processing conditions and methods are not clearly described in the subsequent embodiments, the conditions and methods known in the art can be used for processing.

[0074] Example 1

[0075] (1) The TCO conductive glass (TCO refers to transparent conductive oxide, and the TCO conductive glass in this embodiment includes a glass substrate and an ITO layer located on one side of the glass substrate) is ultrasonically cleaned with deionized water, acetone, and isopropyl alcohol for 15 minutes in sequence, and then placed in a drying oven at 75 °C for drying and standby; the dried TCO conductive glass is placed in an ultraviolet ozone machine for 25 minutes to remove the organic impurities on its surface and optimize its surface wettability at the same time;

[0076] (2) 1 mg of SAM material (2PACz) and 0.1 mg of vinyl acetate are dispersed in 1 mL of ethanol solution and ultrasonically treated for 20 minutes to obtain a composite hole transport material dispersion;

[0077] (3) 30 μL of the above dispersion is taken and dropped on the TCO conductive glass, and spin-coated at a speed of 5000 rpm for 30 s. The TCO conductive glass is placed on a hot stage and annealed at 100 °C for 10 minutes to obtain a composite hole transport layer;

[0078] (4) Dissolve 722.08 mg of lead iodide and 238.50 mg of iodomethylamine solid in 1 mL of N,N-dimethylformamide (DMF), stir at room temperature until completely dissolved to obtain a perovskite precursor solution; in a nitrogen glove box, take 30 μL of the perovskite precursor solution and drop it onto the TCO conductive glass forming the hole transport layer, first spin-coat at 1000 rpm for 10 s, then spin-coat at 5000 rpm for 30 s, and then place the TCO conductive glass on a hot plate and heat-anneal at 100 °C for 40 min to form a perovskite light-absorbing layer with a thickness of 500 nm;

[0079] (5) Dissolve 20 mg of methanofullerene phenyl-C61-butyric acid methyl ester (PCBM) in 1 mL of chlorobenzene, stir at room temperature to obtain a [6,6]-phenyl-C61-butyric acid methyl ester solution; take 30 μL of the [6,6]-phenyl-C61-butyric acid methyl ester solution and drop it onto the TCO conductive glass with a perovskite light-absorbing layer formed thereon, spin-coat at 3000 rpm for 60 s to form an electron transport layer with a thickness of 30 nm;

[0080] (6) Dissolve 0.5 mg of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) in 1 mL of isopropanol, stir at room temperature to obtain a hole blocking layer solution; take 40 μL of the hole blocking layer solution and drop it above the electron transport layer, spin-coat at 5000 rpm for 35 s to form a hole blocking layer with a thickness of 6 nm;

[0081] (7) Transfer the TCO conductive glass with the hole blocking layer, electron transport layer, perovskite light-absorbing layer, and composite hole transport layer formed thereon to a vacuum coating instrument, and when the vacuum degree is pumped to 3×10 -4 Pa, evaporate the silver electrode to form a silver electrode with a thickness of 100 nm on the hole blocking layer, thus obtaining the electrode layer.

[0082] The differences between Examples 2 to 10, Comparative Examples 1 to 3 and Example 1 are recorded in Table 1, and the remaining parameters and steps are the same as those in Example 1.

[0083] The test results of the open-circuit voltage, short-circuit current, fill factor, and photoelectric conversion efficiency of the perovskite solar cells (devices) in each example and comparative example are recorded in Table 1.

[0084] Table 1

[0085]

[0086]

[0087] In Example 10, DMACPA is [4-(2,7-dibromo-9,9-dimethylacridin-10-yl)butyl]phosphoric acid.

[0088] As can be seen from Table 1, compared with the comparative example using only SAM material as the hole transport layer, the composite hole transport layer provided in the present application can improve the photoelectric conversion efficiency and fill factor of the device.

[0089] In the description of the present application, the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and does not require the present application to be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application.

[0090] In the description of this specification, the description with reference to terms such as "some embodiments" and "other embodiments" means that the specific features, structures, materials or characteristics described in connection with the embodiment are included in at least one embodiment of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Additionally, it should be noted that in this specification, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features.

[0091] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as a limitation to the present application. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present application.

Claims

1. A perovskite solar cell, characterized in that: It comprises a composite hole transport layer and a perovskite light absorption layer, wherein the perovskite light absorption layer is located on one side of the composite hole transport layer, and the composite hole transport layer comprises polyvinyl acetate and SAM material.

2. The perovskite solar cell according to claim 1, characterized in that The mass ratio of the SAM material to the polyvinyl acetate is 5:1 to 30:

1.

3. The perovskite solar cell according to claim 1, characterized in that The SAM material includes one or more of a phosphate anchor material with carbazole as the core and a phosphate anchor material with acridine as the core.

4. The perovskite solar cell according to claim 1, characterized in that: The SAM materials include (2-(9H-carbazole-9-yl)ethyl)phosphonic acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid, [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid, [4-(9H-carbazole-9-yl)butyl]phosphonic acid, (4-(3,6-dibromo-9H-carbazole-9-yl)butyl) Phosphonic acid, (2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl)phosphonic acid, (2-(3,6-dibromo-9H-carbazole-9-yl)ethyl)phosphonic acid, [4-(2,7-dibromo-9,9-dimethylacridin-10-yl)butyl]phosphonic acid, [4-(2,7-dimethyl-9,9-dimethylacridin-10-yl)butyl]phosphonic acid, [4-(2,7-diphenyl-9,9-dimethylacridin-10-yl)butyl]phosphonic acid.

5. The perovskite solar cell according to claim 1, characterized in that: The perovskite light absorbing layer comprises a perovskite material, and the general formula of the perovskite material is ABX3, wherein A comprises MA + , FA + , Cs + One or more of, B includes Pb 2 + Sn 2+ One or more of, X includes I - Br - , Cl - One or more of .

6. The perovskite solar cell according to any one of claims 1 to 5, characterized in that The perovskite solar cell further comprises: Conductive glass, the conductive glass comprising a glass substrate and a first electrode layer, wherein the first electrode layer is arranged close to the composite hole transport layer; An electron transport layer, the electron transport layer is located on a side of the perovskite light absorbing layer away from the composite hole transport layer; A second electrode layer, wherein the second electrode layer is located on a side of the electron transport layer away from the perovskite light absorbing layer.

7. The perovskite solar cell according to claim 6, characterized in that: At least one of the following conditions is met: The first electrode layer includes one or more of ITO, FTO, AZO, and GZO; The electron transport layer includes one or more of [6,6]-phenyl-C61-butyric acid methyl ester, C60 and tin oxide; The second electrode layer comprises one or more of silver, copper, carbon and conductive oxide; The perovskite solar cell further comprises an inorganic hole transport layer, wherein the inorganic hole transport layer is located between the conductive glass and the composite hole transport layer; The perovskite solar cell further includes a hole blocking layer, which is located between the electron transport layer and the second electrode layer, and the hole blocking layer includes one or more of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline and zirconium acetylacetonate.

8. A method for preparing a perovskite solar cell, characterized in that: include: forming a composite hole transport layer, wherein the composite hole transport layer comprises polyvinyl acetate and a SAM material; A perovskite light absorbing layer is formed on one side of the composite hole transport layer.

9. The method according to claim 8, characterized in that Forming the composite hole transport layer comprises: Providing a dispersion comprising a SAM material, vinyl acetate and a dispersant; The composite hole transport layer is formed by coating the dispersion and performing an annealing treatment.

10. The method according to claim 9, characterized in that At least one of the following conditions is met: In the dispersion, the mass ratio of the SAM material to vinyl acetate is 5:1 to 30:1; The total concentration of SAM material and vinyl acetate is 0.1 mg / mL to 2 mg / mL; The dispersant includes one or more of ethanol and isopropanol; The method of coating the dispersion includes one or more of spin coating, blade coating, and slit coating; The annealing temperature is 60°C to 150°C; The annealing treatment time is 1 minute to 120 minutes.

11. The method according to any one of claims 8 to 10, characterized in that: The material forming the perovskite light-absorbing layer includes a first perovskite precursor and a second perovskite precursor, wherein the first perovskite precursor includes one or more of lead halide salts and tin halide salts, and the second perovskite precursor includes one or more of formamidine halide salts, methylamine halide salts and cesium halide salts.

12. A battery module, characterized in that: The invention comprises a plurality of perovskite solar cells according to any one of claims 1 to 7 or a perovskite solar cell prepared by the method according to any one of claims 8 to 11.

13. A laminated battery, characterized in that: The invention comprises a first battery and a second battery arranged in a stacked manner, wherein at least one of the first battery and the second battery comprises the perovskite solar cell according to any one of claims 1 to 5 or a perovskite solar cell prepared by the method according to any one of claims 8 to 11.

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